Doubled acid azo dyes with a hydroxypyridone coupling component

ABSTRACT

Azo dyes of the formula ##STR1## where D is the radical of a diazo component, and 
     X is substituted or unsubstituted C 2  -C 8  -alkylene, in the form of the free acid or its salts, the use thereof for dyeing or printing natural or synthetic substrates, sulfopyridones as coupling components for these dyes, and a process for preparing them.

The present invention relates to novel azo dyes of the formula I ##STR2## where D is the radical of a diazo component, and

X is C₂ -C₈ -alkylene with or without interruption by an oxygen atom in ether function,

in the form of the free acid or its salts, to the use thereof for dyeing or printing natural or synthetic substrates, to sulfopyridones as coupling components for these dyes, and to a process for preparing them.

It is an object of the present invention to provide novel azo dyes which have doubled 3-hydroxysulfonyl-4-methyl-6-hydroxypyrid-2-ones as coupling component and advantageous application properties.

We have found that this object is aclhieved by the above-defined azo dyes of the formula I.

The novel azo dyes of the formula I can be present either in the form of the free acid or else as salts.

Suitable salts are metal or ammonium salts. Metal salts include in particular the lithium, sodium or potassium salts. Ammonium salts for the purposes of the present invention are salts with subtituted or unsubstituted ammonium cations. Substituted ammonium cations include for example monoalkyl-, dialkyl-, trialkyl-, tetraalkyl- or benzyltrialkyl-ammoniumcations or cations derived from nitrogen-containing five- or six-membered saturated heterocycles, such as pyrrolidinium, piperidinium, morpholinium, piperazinium or N-alkylpiperaziniumcations or their N-monoalkyl- or N,N-dialkyl-substituted products. Alkyl for the purposes of the present invention is generally straight-chain or branched C₁ -C₂₀ -alkyl which may be substituted by hydroxyl groups and/or may be interrupted by from 1 to 4 oxygen atoms in ether function. Any alkyl or alkylene appearing in the abovementioned formula may be straight-chain or branched.

X is for example CH₂, (CH₂)₂, (CH₂)₃, (CH₂)₄, (CH₂)₅, (CH₂)₆, (CH₂)₇, (CH₂)₈, CH(CH₃ )CH₂ , CH(CH₃)CH(CH₃), C₂ H₄ OC₂ H₄, C₃ H₆ OC₂ H₄, C₃ H₆ OC₃ H₆, C₄ H₈ OC₃ H₆ or C₄ H₈ OC₄ H₈.

Of importance are azo dyes of the formula I where D is the radical of a diazo component derived from an aniline, from an aminonaphthalene or from a five-membered aromatic heterocyclic amine which contains from one to three hetero atoms selected from the group consisting of nitrogen, oxygen and sulfur in the heterocyclic ring with or without a fused-on benzene, thiophene, pyridine or pyrimidine ring.

Important azo dyes of the formula I are those where D is the radical of a diazo component derived from an aniline, from an aminonaphthalene or from a heterocyclic amine of the pyrrole, furan, thiophene, pyrazole, imidazole, oxazole, isoxazole, thiazole, isothiazole, triazole, oxadiazole, thiadiazole, benzofuran, benzothiophene, benzimidazole, benzoxazole, benzothiazole, benzisothiazole, pyridothiophene, pyrimidothiophene, thienothiophene or thienothiazole series.

Of particular importance are azo dyes of the formula I where D is the radical of a diazo component derived from an aniline or from an aminonaphthalene, anilines being especially important.

Of industrial significance are azo dyes of the formula I where D is the radical of a diazo component derived from an aminobenzophenone, from an aminoazobenzene or from an aminobenzoic acid.

D radicals conform for example to the formula ##STR3## where L¹ is nitro, cyano, C₁ -C₆ -alkanoyl, benzoyl, C₁ -C₆ -alkylsulfonyl, substituted or unsubstituted phenylsulfonyl or a radical of the formula --CH═T, where T is hydroxyimino, C₁ -C₄ -alkoxyimino or a radical of an acidic CH compound,

L² is hydrogen, C₁ -C₆ -alkyl, halogen, hydroxyl, mercapto, unsubstituted or phenyl- or C₁ -C₄ -alkoxy-substituted C₁ -C₆ -alkoxy, substituted or unsubstituted phenoxy, unsubstituted or phenyl-substituted C₁ -C₆ -alkylthio, substituted or unsubstituted phenylthio, C₁ -C₆ -alkylsulfonyl or substituted or unsubstituted phenylsulfonyl,

L³ is cyano, C₁ -C₄ -alkoxycarbonyl, carboxyl or nitro,

L⁴ is hydrogen, C₁ -C₆ -alkyl or phenyl,

L⁵ is C₁ -C₆ -alkyl or phenyl,

L⁶ is hydrogen, cyano, C₁ -C₄ -alkoxycarbonyl, carboxyl, C₁ -C₆ -alkanoyl, thiocyanato or halogen,

L⁷ is nitro, cyano, C₁ -C₆ -alkanoyl, benzoyl, C₁ -C₄ -alkoxycarbonyl, carboxyl, C₁ -C₆ -alkylsulfonyl, substituted or unsubstituted phenylsulfonyl or a radical of the formula --CH═T, where T is as defined above,

L⁸ is hydrogen, C₁ -C₆ -alkyl, cyano, halogen, unsubstituted or phenyl- or C₁ -C₄ -alkoxy-substituted C₁ -C₆ -alkoxy, unsubstituted or phenyl-substituted C₁ -C₆ -alkylthio, substituted or unsubstituted phenylthio, C₁ -C₆ -alkylsulfonyl, substituted or unsubstituted phenylsulfonyl, C₁ -C₄ -alkoxycarbonyl or carboxyl,

L⁹ is cyano, unsubstituted or phenyl-substituted C₁ -C₆ -alkyl, unsubstituted or phenyl-substituted C₁ -C₆ -alkylthio, substituted or unsubstituted phenyl, thienyl, C₁ -C₄ -alkylthienyl, pyridyl or C₁ -C₄ -alkylpyridyl,

L¹⁰ is phenyl or pyridyl,

L¹¹ is trifluoromethyl, nitro, C₁ -C₆ -alkyl, phenyl, unsubstituted or phenyl-substituted C₁ -C₆ -alkylthio or di(C₁ -C₆ -alkyl)amino,

L¹² is C₁ -C₆ -alkyl, phenyl, 2-cyanoethylthio or 2-(C₁ -C₄ -alkoxycarbonyl)ethylthio,

L¹³ is hydrogen, nitro or halogen,

L¹⁴ is hydrogen, cyano, C₁ -C₄ -alkoxycarbonyl, carboxyl, nitro or halogen,

L¹⁵ and L¹⁶ are identical or different and each is independently of the other hydrogen, C₁ -C₆ -alkyl, C₁ -C₆ -alkoxy or halogen,

L¹⁷ is hydrogen, C₁ -C₆ -alkyl, trifluoromethyl, C₁ -C₆ -alkanoyl, substituted or unsubstituted benzoyl, C₁ -C₄ -alkoxycarbonyl, hydroxysulfonyl, substituted or unsubstituted phenylsulfonyl-oxy, mono- or di(C₁ -C₄ -alkyl)carbamoyl, mono- or di(C₁ -C₄)-alkylsulfamoyl, C₁ -C₄ -alkanoylamino, hydroxysulfonyl- or carboxylphenyl-azo, 5-(C₁ -C₄ -alkyl)-1,2,4-oxadiazol-3-yl or 6-hydroxysulfonyl-7-methylbenzothiazol-2-yl, and

the ring A may have a fused-on benzene or hydroxysulfonylbenzene ring.

Any alkyl or alkylene appearing in the abovementioned formulae may be straight-chain or branched.

Any substituted phenyl appearing in tlhe abovementioned formulae of the azo dyes may contain as substituents for example C₁ -C₄ -alkyl, chlorine, bromine, nitro or C₁ -C₄ -alkoxy. The number of substituents in substituted phenyl is generally from 1 to 3.

The number of substituents in substituted alkyl is generally 1 or 2.

L², L⁴, L⁵, L⁸, L⁹, L¹¹, L¹², L¹⁵, L¹⁶ and L¹⁷ are each for example methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, pentyl, isopentyl, neopentyi, tert-pentyl, hexyl or 2-methylpentyl.

L⁹ may also be for example benzyl or 1- or 2-phenylethyl.

L², L⁸, L⁹ and L¹¹ may each also be for example methylthio, ethylthio, propylthio, isopropyithio, butylthio, isobutylthio, pentylthio, hexylthio, benzylthio or 1- or 2-phenylethylthio.

L² and L⁸ may each also be for example phenylthio, 2-methylphenylthio, 2-methoxyphenyithio or 2-chlorophenylthio.

L², L⁸, L¹⁵ and L¹⁶ may each also be for example methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, pentyloxy, isopentyloxy, neopentyloxy, tert-pentyloxy, hexyloxy or 2-methylpentyloxy.

L², L⁸, L¹³, L¹⁴, L¹⁵ and L¹⁶ may each also be for example fluorine, chlorine or bromine.

L⁷, as well as L¹, L² and L⁸, is for example methylsulfonyl, ethylsulfonyl, propylsulfonyl, isopropylsulfonyl, butylsulfonyl, isobutylsulfonyl sec-butylsulfonyl, pentylsulfonyl, isopentylsulfonyl, neopentylsulfonyl, hexylsulfonyl, phenylsulfonyl, 2-methylphenylsulfonyl, 2-methoxyphenylsulfonyl or 2-chlorophenylsulfonyl.

L³, as well as L⁶, L⁷, L⁸, L¹⁴ and L¹⁷ is for example methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, isobutoxycarbonyl or sec-butoxycarbonyl.

L² and L⁸ may each also be for example 2-methoxyethoxy, 2-ethoxyethoxy, 2- or 3-methoxypropoxy, 2-or 3-ethoxypropoxy, 2- or 4-methoxybutoxy, 2- or 4-ethoxybutoxy, 5-methoxypentyloxy, 5-ethoxypentyloxy, 6-methoxyhexyloxy, 6-ethoxyhexyloxy, benzyloxy or 1- or 2-phenylethoxy.

L¹¹ may also be for example dimethylamino, diethylamino, dipropylamino, diisopropylamino, dibutylamino, dipentylamino, dihexylamino or N-methyl-N-ethylamino.

L¹² may also be for example 2-methoxycarbonylethylthio or 2-ethoxycarbonylethylthio.

L⁹ may also be for example phenyl, 2-, 3- or 4-methylphenyl, 2,4-dimethylphenyl, 2-, 3- or 4-methoxyphenyl, 2-, 3- or 4-chlorophenyl, 2-, 3- or 4-methoxyphenyl, 2- or 3-methylthienyl or 2-, 3- or 4-methylpyridyl.

L¹ L⁶, L⁷ and L¹⁷ may each also be for example formyl, acetyl, propionyl, butyryl, pentanoyl or hexanoyl.

L¹⁷ may also be for example benzoyl, 2-, 3- or 4-methylbenzoyl, 2-, 3- or 4-ethylbenzoyl, 2-, 3- or 4-propylbenzoyl, 2-, 3- or 4-isopropylbenzoyl, 2,3-, 2,4-, 2,5-, 2,6-, 3,4- or 3,5-dimethylbenzoyl, 2-methyl-4-methoxybenzoyl, 2-, 3- or 4-methoxybenzoyl, 2-, 3- or 4-ethoxybenzoyl, phenylsulfonyloxy, 2-, 3- or 4-methylphenylsulfonyloxy, mono- or dimethylcarbamoyl, mono- or diethylcarbamoyl, mono- or dipropylcarbamoyl, mono- or diisopropylcarbamoyl, mono- or dibutylcarbamoyl, mono- or dimethylsulfamoyl, mono- or diethylsulfamoyl, mono- or dipropylsulfamoyl, mono- or diisopropylsulfamoyl, mono- or dibutylsulfamoyl, formylamino, acetylamino, propionylamino, butyrylamino, isobutyrylamino, 4-hydroxysulfonylphenylazo, 4-carboxylphenylazo, 5-methyl-1,2,4-oxadiazol-3-yl or 5-ethyl-1,2,4-oxadiazol-3-yl.

When L¹ or L⁷ is the radical --CH═T where T is derived from an acidic CH compound H₂ T, suitable acidic CH compounds H₂ T include for example compounds of the formula ##STR4## where Z¹ is cyano, nitro, C₁ -C₄ -alkanoyl, substituted or unsubstituted benzoyl, C₁ -C₄ -alkylsulfonyl, substituted or unsubstituted phenylsulfonyl, carboxyl, C₁ -C₄ -alkoxycarbonyl, C₃ -C₄ -alkenyloxycarbonyl, phenoxycarbonyl, carbamoyl, mono- or di(C₁ -C₄ -alkyl) carbamoyl, substituted or unsubstituted phenylcarbamoyl, substituted or unsubstituted phenyl, benzothiazol-2-yl, benzimidazol-2-yl, 5-phenyl-1,3,4-thiadiazol-2-yl or 2-hydroxychinoxalin-3-yl,

Z² is C₁ -C₄ -alkyl, C₁ -C₄ -alkoxy or C₃ -C₄ -alkenyloxy,

Z³ is C₁ -C₄ -alkoxycarbonyl, C₃ -C₄ -alkenyloxycarbonyl, phenylcarbamoyl or benzimidazol-2-yl,

Z⁴ is cyano, C₁ -C₄ -alkoxycarbonyl or C₃ -C₄ -alkenyloxycarbonyl,

Z⁵ is hydrogen or C₁ -C₆ -alkyl,

Z⁶ is hydrogen, C₁ -C₄ -Alkyl or phenyl and

Z⁷ is C₁ -C₄ -alkyl.

Attention is drawn to the radical derived from compounds of the formula IIIa, IIIb or IIIc where Z¹ is cyano, C₁ -C₄ -alkanoyl, C₁ -C₄ -alkoxycarbonyl or C₃ -C₄ -alkenyloxycarbonyl, Z² is C₁ -C₄ -alkyl, C₁ -C₄ -alkoxy or C₃ -C₄ -alkenyloxy, Z³ is C₁ -C₄ -alkoxycarbonyl or C₃ -C₄ -alkenyloxycarbonyl and Z⁴ is cyano.

Particular attention is drawn to the radical derived from compounds of the formula IIIa, IIIb or IIIc where Z¹ is cyano, C₁ -C₄ -alkoxycarbonyl or C₃ -C₄ -alkenyloxycarbonyl, Z² is C₁ -C₄ -alkoxy or C₂ -C₄ -alkenyloxy, Z³ is C₁ -C₄ -alkoxycarbonyl or C₃ -C₄ -alkenyloxycarbonyl and Z⁴ is cyano.

Preference is given to azo dyes of the formula Ia ##STR5## where L¹⁵, L¹⁶, L¹⁷, X and the ring A are each as defined above.

Particular preference is given to azo dyes of the formula Ib ##STR6## where X is as defined above, L¹⁵ and L¹⁶ are each hydrogen and L¹⁷ is substituted or unsubstituted benzoyl, or L¹⁵ and L¹⁶ are, independently of each other, hydrogen, C₁ -C₄ -alkyl or C₁ -C₄ -alkoxy and L¹⁷ is hydroxysulfonylphenylazo or carboxylphenylazo.

Particular preference is further given to azo dyes of the formula Ic ##STR7## where one of Z¹ and Z² is hydrogen and the other is C₁ -C₄ -alkoxycarbonyl and X is as defined above.

The azo dyes of the formula I according to the present invention can be obtained in a conventional manner, for example by diazotizing an amine of the formula IV

    D--NH.sub.2                                                (IV),

where D is as defined above, and coupling the resulting diazonium salt with a sulfopyridone of the formula V ##STR8## where X is as defined above.

The present invention further provides sulfopyridones of the formula V ##STR9## where X is C₂ -C₈ -alkylene with or without interruption by an oxygen atom in ether function, in the form of the free acid or its salts.

The invention also provides an advantageous process for preparing the sulfopyridones of the formula V, which comprises treating a cyanopyridone of the formula VI ##STR10## where X is as defined above, in concentrated sulfuric acid at from 80° to 130° C.

Preferably the novel process is carried out at from 90° to 125° C.

Concentrated sulfuric acid for the purposes of the present invention is from 96 to 98 % strength by weight sulfuric acid. Generally from 2 to 2.5 parts by weight of concentrated sulfuric acid are used per part by weight of cyanopyridone VI.

The novel process is generally carried out by using concentrated sulfuric acid as initial charge and adding the cyanopyridone VI to it at room temperature. The temperature will rise and is allowed to increase to about 60°-70° C. This is followed by a period of stirring at the temperature of the present invention. The reaction will generally end after 5-8 hours, and the reaction mixture is then cooled down. It can then be added to an ice-water mixture and be neutralized. The solution thus obtained can be used directly for preparing the azo dyes of the formula I.

It can be of advantage to have small amounts of sulfur trioxide present, in which case the reaction medium is for example from 2 to 5% strength by weight oleum.

The azo dyes of the formula I according to the present invention are advantageously suitable for dyeing natural or synthetic substrates, for example wool, leather or polyamide. The dyeings obtained have good allround fastnesses.

The Examples which follow illustrate the invention.

EXAMPLE 1

163 g of the cyanopyridone of the formula ##STR11## were introduced into a mixture of 40 g of oleum (24% strength by weight) and 380 g of sulfuric acid (100% strength by weight). The temperature was allowed to rise from 15° C. at the start of the addition to a maximum of 70° C. The mixture was stirred at from 70° to 80° C. for 2 h and then heated to 90° C. to split off CO₂. Then the reaction temperature was raised over about 4 h to 130°-135° C. in such a way that the elimination of CO₂ could be controlled. This was followed by stirring at from 130° to 135° C. for a further 6 h.

The melt obtained on cooling was poured with stirring onto about 1000 g of ice and 500 ml of water, and the resulting precipitation was adjusted with sodium hydroxide solution to pH 7 while cooling at <40° C. The result obtained was a clear solution (which can precipitate sodium sulfate on standing) of the sulfopyridone of the formula ##STR12##

EXAMPLE 2

340 g of the cyanopyridone of the formula ##STR13## were introduced into a mixture of 760 g of sulfuric acid (100% strength by weight) and 80 g of oleum (24% strength by weight) and reacted as described in Example 1. About 0.97 mol was obtained of the sulfopyridone of the formula ##STR14## in the form of an aqueous solution.

EXAMPLE 3

30 g of 4-amino-4-methylbenzophenone hydrochloride were stirred up in 55 ml of 17% strength by weight hydrochloric acid. The mixture was then cooled down to 0° C., about 40 g of ice and at the same time 20 ml of 23% strength by weight aqueous sodium nitrite solution were added in such a way that the temperature of the diazotization batch did not rise above 10° C. The batch was subsequently stirred for a further 1 h while being cooled down with ice to 0°-5° C. After excess nitrous acid was destroyed, the pH of the resulting diazonium salt solution was raised with a little sodium acetate and sodiumhydroxide solution to 5-6 at < 0° C. Then 14.85 g of the sulfopyridone of the formula ##STR15## were added as an aqueous solution over 20 min while the pH was maintained within the range 4 to 7.5 by addition of sodium hydroxide solution.

The dye of the formula ##STR16## came down as a crystalline precipitate and was isolated at pH 7 in the form of the disodium salt by salting out. Drying left 45 g of a yellow powder which gives a yellow solution in water. Dyeing 100 g of retanned chrome cattlehide leather with 0.8 g of this dye by the conventional dyeing processes gives a strong lemon yellow surface dyeing with a bright hue.

Polycaprolactam fabric is dyed by conventional dyeing processes in bright, strong, lemon yellow shades, while wool is dyed in deep neutral yellow shades.

EXAMPLE 4

10 g of ethyl 4-aminobenzoate were diazotized by the method of Example 3. Excess nitrous acid was destroyed, the pH of the diazonium salt solution was raised with a little sodium acetate and sodium hydroxide solution to 4.5-6.5 at 0° C., and then 14.85 g of the sulfopyridone mentioned in Example 2 were added in the form of an aqueous solution while the pH of the coupling batch was maintained within the above-specified range. This yielded 25 g of the dye of the formula ##STR17## Isolation at about pH 6.5 and drying were carried out as usual. The dye gives a yellow solution in water and dyes leather, polycaprolactam and wool in strong, lemon yellow to golden yellow hues. The dyeings have good light and wet fastnesses.

EXAMPLE 5

16.7 g of 4-aminoazobenzene-4-sulfonic acid were dissolved in 100 ml of water with sodium hydroxide solution at pH 8-9 and elevated temperature. Then 20 ml of 23% strength by weight aqueous sodium nitrite solution were added and the batch was allowed to cool down with stirring. After cooli. ng with ice down to 0° C., the batch was acidified with 20 ml of concentrated hydrochloric acid. The suspension obtained was stirred at from 0° to 5° C. for 4 h. Then excess nitrous acid was destroyed, the pH of the suspension was raised with a little sodium acetate and sodium hydroxide solution to 4.5-5.5, and an aqueous solution of 14.5 g of the sodium salt of the coupling component described in Example 1 was added similarly to Example 4. Then the reaction mixture was adjusted with sodium hydroxide solution to pH 5.5. The resulting dye was precipitated with sodium chloride, and the precipitate was isolated and dried as usual to leave 31 g of a reddish orange powder of the formula ##STR18## which gives a golden yellow solution in water. The dye dyes wool, polycaprolactam and leather in a deep orange shade with good fastness properties.

The methods of Examples 1 to 5 also give the dyes described below in Tables 1 and 2.

                                      TABLE 1                                      __________________________________________________________________________      ##STR19##                                                                     Ex.                                λ.sub.max [nm]                       No.                                                                               n D                     Hue     (in water)                                  __________________________________________________________________________      6 2                                                                                 ##STR20##            lemon yellow                                                                           406                                          7 3                                                                                 ##STR21##            lemon yellow                                         8 4                                                                                 ##STR22##            lemon yellow                                         9 2                                                                                 ##STR23##            lemon yellow                                                                           408                                         10 2                                                                                 ##STR24##            lemon yellow                                        11 2                                                                                 ##STR25##            lemon yellow                                        12 2                                                                                 ##STR26##            lemon yellow                                        13 2                                                                                 ##STR27##            lemon yellow                                        14 2                                                                                 ##STR28##            lemon yellow                                        15 3                                                                                 ##STR29##            lemon yellow                                        16 2                                                                                 ##STR30##            lemon yellow                                        17 2                                                                                 ##STR31##            lemon yellow                                        18 2                                                                                 ##STR32##            lemon yellow                                        19 2                                                                                 ##STR33##            greenish yellow                                     20 2                                                                                 ##STR34##            neutral yellow                                      21 3                                                                                 ##STR35##            neutral yellow                                      22 4                                                                                 ##STR36##            neutral yellow                                      23 4                                                                                 ##STR37##            neutral yellow                                      24 2                                                                                 ##STR38##            neutral yellow                                      25 3                                                                                 ##STR39##            neutral yellow                                      26 2                                                                                 ##STR40##            greenish yellow                                     27 3                                                                                 ##STR41##            greenish yellow                                     28 4                                                                                 ##STR42##            greenish yellow                                     29 2                                                                                 ##STR43##            greenish yellow                                     30 3                                                                                 ##STR44##            greenish yellow                                     31 2                                                                                 ##STR45##            greenish yellow                                     32 3                                                                                 ##STR46##            greenish yellow                                     33 2                                                                                 ##STR47##            greenish yellow                                     34 3                                                                                 ##STR48##            greenish yellow                                     35 4                                                                                 ##STR49##            greenish yellow                                     36 2                                                                                 ##STR50##            greenish yellow                                     37 2                                                                                 ##STR51##            greenish yellow                                     38 2                                                                                 ##STR52##            neutral yellow                                      39 2                                                                                 ##STR53##            neutral yellow                                      40 2                                                                                 ##STR54##            greenish yellow                                     41 3                                                                                 ##STR55##            greenish yellow                                     42 4                                                                                 ##STR56##            greenish yellow                                     43 2                                                                                 ##STR57##            orange                                              44 3                                                                                 ##STR58##            orange                                              45 2                                                                                 ##STR59##            orange                                              46 3                                                                                 ##STR60##            orange                                              47 2                                                                                 ##STR61##            orange                                              48 3                                                                                 ##STR62##            orange                                              49 2                                                                                 ##STR63##            orange                                              50 2                                                                                 ##STR64##            orange                                              51 3                                                                                 ##STR65##            orange                                              52 2                                                                                 ##STR66##            orange                                              53 2                                                                                 ##STR67##            orange                                              54 3                                                                                 ##STR68##            orange                                              55 2                                                                                 ##STR69##            neutral yellow                                      56 2                                                                                 ##STR70##            orange                                              57 3                                                                                 ##STR71##            orange                                              58 2                                                                                 ##STR72##            orange                                              59 2                                                                                 ##STR73##            greenish yellow                                     60 2                                                                                 ##STR74##            neutral yellow                                      61 3                                                                                 ##STR75##            neutral yellow                                      62 2                                                                                 ##STR76##            neutral yellow                                      63 3                                                                                 ##STR77##            neutral yellow                                      64 2                                                                                 ##STR78##            neutral yellow                                      65 2                                                                                 ##STR79##            greenish yellow                                     __________________________________________________________________________

                                      TABLE 2                                      __________________________________________________________________________      ##STR80##                                                                     Ex.                                                                            No.                                                                               D                     n W Y  Hue                                            __________________________________________________________________________     66                                                                                 ##STR81##            1 --                                                                               CH.sub.3                                                                          greenish yellow                                67                                                                                 ##STR82##            1 --                                                                               CH.sub.3                                                                          greenish yellow                                68                                                                                 ##STR83##            1 --                                                                               CH.sub.3                                                                          greenish yellow                                69                                                                                 ##STR84##            1 --                                                                               CH.sub.3                                                                          greenish yellow                                70                                                                                 ##STR85##            1 --                                                                               CH.sub.3                                                                          greenish yellow                                71                                                                                 ##STR86##            1 --                                                                               CH.sub.3                                                                          greenish yellow                                72                                                                                 ##STR87##            1 --                                                                               CH.sub.3                                                                          greenish yellow                                73                                                                                 ##STR88##            1 --                                                                               CH.sub.3                                                                          greenish yellow                                74                                                                                 ##STR89##            1 --                                                                               CH.sub.3                                                                          greenish yellow                                75                                                                                 ##STR90##            1 --                                                                               CH.sub.3                                                                          orange                                         76                                                                                 ##STR91##            1 --                                                                               CH.sub.3                                                                          orange                                         77                                                                                 ##STR92##            1 --                                                                               CH.sub.3                                                                          orange                                         78                                                                                 ##STR93##            1 --                                                                               CH.sub.3                                                                          orange                                         79                                                                                 ##STR94##            1 --                                                                               CH.sub.3                                                                          orange                                         80                                                                                 ##STR95##            1 --                                                                               CH.sub.3                                                                          orange                                         81                                                                                 ##STR96##            3 --                                                                               H  greenish yellow                                82                                                                                 ##STR97##            4 O H  greenish yellow                                83                                                                                 ##STR98##            3 --                                                                               H  greenish yellow                                84                                                                                 ##STR99##            4 O H  greenish yellow                                85                                                                                 ##STR100##           1 --                                                                               H  orange                                         __________________________________________________________________________ 

We claim:
 1. An azo dye of the formula I ##STR101## where D is the radical of a diazo component, andX is C₂ -C₈ -alkylene with or without interruption by an ether oxygen atom,in the form of the free acid or its salts.
 2. The azo dye as claimed in claim 1, wherein D is the radical of an aniline, an amino-naphthalene or a five-membered aromatic heterocyclic amine which contains from one to three hetero atoms selected from the group consisting of nitrogen, oxygen and sulfur in the heterocyclic ring with or without a fused-on benzene, thiophene, pyridine or pyrimidine ring, diazo component.
 3. The azo dye as claimed in claim 1, wherein D is the radical of an aniline, an amino-naphthalene, a pyrrole, a furan, a thiophene, a pyrazole, an imidazole, an oxazole, an isoxazole, a thiazole, an isothiazole, a triazole, an oxadiazole, a thiadiazole, a benzofuran, a benzothiophene, a benzimidazole, a benzoxazole, a benzothiazole, a benzisothiazole, a pyridothiophene, a pyrimidothiophene, a thienothiophene or a thienothiazole diazo component.
 4. The azo dye as claimed in claim 1, wherein D is the radical of an aniline or an amino-naphthalene diazo component.
 5. The azo dye as claimed in claim 1, wherein D is the radical of an aniline diazo component.
 6. The azo dye as claimed in claim 1, wherein D is the radical of an aminobenzophenone, an aminoazobenzene or an aminobenzoic acid diazo component.
 7. A method of dyeing or printing natural or synthetic substrates which comprises applying an azo dye of claim 1 to said substrate. 